@GB Bluetooth remote control instructions . The first use (or replace the battery) need to matching frequency Step 1. Install two AAA 1.5V batteries, (note the positive and negative polarity inside the battery chamber), and finally close the battery cover, indicator will flash three times indicates that the battery is installed correctly. Step 2. Press and hold the frequency key(car select) for about 2 seconds and the indicator will flash Step 3. Turn on the power supply of the car and the indicator will turn off Step 4. If the matching frequency is unsuccessful (indicator not turn off), please turn off the power supply and repeat steps 2 and 3. RX23 replaces RX18 and RX7 RX19 replaces RX12 RX71replaces RX37 RX74replaces RX30 Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store